Skip to Content

Wiki source code of WebObjects with Scala

Version 249.1 by Ravi Mendis on 2009/09/15 20:43
Show last authors
1 === What is Scala? ===
2
3 Scala is a modern language not unlike Groovy.
4 It is said to be more powerful (and faster) than Groovy or Rails which has been the reason for its adoption at sites like Twitter.
5
6 Many of its features and paradigms favor multi-threaded and concurrent development which may not be unfamiliar to Objective-C developers:
7
8 |= |= Objective-C |= Java |= Scala
9 |= Mutable/Immuable Datatypes |Collections //e.g: NSArray/NSMutableArray// | No | //All datatypes//
10 |= Closures | //Extension// | No | //Built-in//
11 |= Static variables | Yes | Yes | No
12 |= Static methods/functions | Yes | Yes | No
13 |= Concurrency | Grand Central Dispatch (//Extension//) | //Threads// | Actors
14
15 Other notable features include:
16
17 |= |= Objective-C |= Java |= Scala
18 |= Parametered methods | Yes //e.g: addObject: to~:// | No | Yes //e.g: add(object= ,to=)//
19 |= Class composition | Categories | Interfaces | Traits
20
21 A fuller description of Scala can be found [[here>>http://en.wikipedia.org/wiki/Scala_(programming_language)]].
22
23 === Why Use Scala? ===
24
25 With Web 2.0, building concurrent WebObjects applications is a must.
26 Developing and maintaining a concurrent or multi-threaded WebObjects application can be challenging.
27
28 Scala offers concurrency built into the language.
29 So it may offer new solutions to allowing concurrency in WebObjects.
30
31 === Can WebObjects be Programmed With Scala? ===
32
33 Yes. It is very simple.
34 Scala compiles to java bytecode. Hence using it with WebObjects is fairly straightforward.
35
36 == How to Develop WebObjects With Scala ==
37
38 1. [[Install the Scala eclipse IDE>>http://www.scala-lang.org/node/94]]
39 1. Add Scala support to your project
40 11. Right-click your project in the WO Explorer
41 11. In the context menu select Scala -> Add Scala Nature
42 1. Convert or use ##.scala## instead of ##.java## source
43
44 {{note title="Note"}}
45
46 This is for Eclipse/WOLips developers
47
48 {{/note}}
49
50 == WO Scala Example ==
51
52 The following is a mixed Java/Scala version of the WO Movies D2W app.
53 All the EO logic and WO components are in Scala.
54 Only the Application class is Java.
55
56 {{attachments patterns=".*zip"}}{{/attachments}}
57
58 === Setup ===
59
60 1. Install and run the OpenBase OBMovies database.
61 1. Right-click on Application.java and run as a WOApplication (as usual).
62
63 ==== EO Templates ====
64
65 See: [[Scala templates>>http://wiki.objectstyle.org/confluence/display/WOL/EOGenerator+Templates+and+Additions]]